Accumulation section for a conveyor

ABSTRACT

The invention relates to a conveyor system in which a series of pallets are moved on rails by means of individual driving wheels spaced along the track for frictional engagement with the underside of the pallets; a lever system is used to engage the individual wheels with a common belt drive power source or to brake the individual wheels when not being driven.

United States Patent 72] Inventors Wolfgang Koennecke Bad HamburgVor-der Hohe; Reinhold Stricker, Frankfurt am Main, both of Germany [21]Appl. No. 844,792

[22] Filed July 25,1969

[45] Patented Nov. 2, 1971 [73] Assignee Flughafen Frankfurt am MainAktiengesellschaft Flughafen Frankfurt am Main, Germany [32] PriorityAug. 1, 1968 [33] Germany [54] ACCUMULATION SECTION FOR A CONVEYOR 6Claims, 4 Drawing Figs.

[52] U.S. Cl

res/127 [51] Int. Cl 865g 13/02 [50] Field of Search 198/127 [56]References Cited UNIT ED STATES PATENTS 2,940,550 6/1960 Mathews 188/743,451,527 6/1969 Leach 198/127 Primary Examiner-Edward A. SrokaAttorney-Christen and Sabol ABSTRACT: The invention relates to aconveyor system in which a series of pallets are moved on rails by meansof individual driving wheels spaced along the track for frictionalengagement with the underside of the pallets; a lever system is used toengage the individual wheels with a common belt drive power source or tobrake the individual wheels when not being driven.

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SHEET 2 OF 2 ACCUMULATION SECTION FOR A CONVEYOR This invention relatesto an accumulation section for a pallet conveyor comprising drive wheelswhich normally act on the underside of the pallets, which are mounted onsupport rails and which are set in rotation by V-belts, wherein thedrive wheels may have one special drive per support rail, to act on theV-belts, according to our copending Pat. application Ser. No. 844,795,filed concurrently with this application, entitled "Pallet Conveyor.

In front of loading stations or deflectors in conveyors socalledaccumulation sections are required, where approaching pallets arebrought to a standstill in such a way that they either touch one anotheror stop a short distance away from one another.

The different forms of such accumulation sections are commerciallyavailable, but for conventional roller conveyors. In one system, therollers are driven by a rubberband on their underside. The whole lengthof the band may be lowered, so that no further drive is imparted to therollers. The disconnection of the drive is initiated by a lever with anattached feeler roller, which is controlled by a first pallet.

In the other system, in which rollers are driven at the sides byV-belts, the drive for the V-belt is provided below the actual conveyortrack by means of a frictional wheel adjacent a motor. When one pallethas been decelerated, the frictional wheel is lifted off the motor bymeans of a lever with a feeler roller, so that the rollers can no longerbe driven. A brake acting laterally on the rollers is also provided, itsaction depending on the weight of the pallets above it.

In the other accumulation section described in German Pat. SpecificationNo. 1,138,693 pallets which have a lateral rim and which are conveyed ona rubber belt, are raised by wheels engaging laterally below the rims ofthe pallets, when the pal lets have to be stopped, for example before adeflector.

The disadvantage of these accumulation sections is that they only permitslight deceleration, partly because of the low friction of the palletson the iron rollers, and partly because the drive itself is not designedfor great deceleration. A disadvantage of the commercial systems is thatmany components project considerably from the profile of the tracktowards the foundation, particularly the drive motors for the rubberbelts and the frictional wheels for the V-belt drive.

According to the present invention, the V-belt drive may be disconnectedat the shaft of the drive wheels.

in the accumulation section according to the present invention theelements which interrupt the flow of power to the drive wheels-beingprovided actually on the drive wheel in question are accommodated withinthe profile of the track between the two support rails.

in a surprisingly simple apparatus of this type, comprising V-beltsextending continuously over a plurality of drive wheels and arranged tobe pressed onto V-belt pulleys by tensioning pulleys, the tensioningrollers are both arranged on a lever which may be pivoted out of theposition in which it presses the belt against the pulley, in order todisconnect the drive, and an additional lifting roller is provided onthe lever to lift the upper run of the belt offthe pulley.

It is advisable for the lever to be connected to the shaft of the drivewheel. This dispenses with the bearing for the lever, which wouldotherwise be necessary.

It is equally possible for the drive for the drive wheel to bedisconnected by means of a clutch provided on its shaft, particularly asingle-plate clutch.

An embodiment of this type may also be accommodated within the profileof the track.

Embodiments of the invention will now be described by way of examplewith reference to the accompanying drawings in which:

FIG. 1 shows the construction of a drive wheel for an accumulationsection according to the invention with a belt-tensioning rollerprovided on an articulated lever;

HO. 2 shows a drive wheel provided with a single-plate clutch;

FIG. 3 is a front elevation of a drive wheel which can additlonully bebraked; and

FIG. 4 is a plan view of part of FIG. 3. X

In FIG. 1 a drive wheel 2 is overhung mounted on a support rail 1 by anaxle. A pulley 5 for a V -belt 3 is also provided on the shaft. Thedrive wheel 2 is rotated by the belt 3 and pulley 5, and the pulley 5 isaccordingly frictionally connected to the wheel 2.

A lever 69 is also pivoted to the said shaft. It is arranged to pivotabout a transverse axis 68 which coincides with the Ian gitudinal axisof the first-mentioned axle.

The lever 69 carries belt-tensioning rollers 70 and 71 respectively, ateach end. The roller 70 urges the lower run 3 of the V-belt 3 intofrictional connection with the pulley 5, while the roller 71 urges theupper run 3" into frictional connection with the pulley 5. The lever 69is additionally provided with a lifting roller 72, which is arrangedbelow the upper run 3". When the tensioning rollers 70, 71 are moveddownwards and upwards respectively by means of the lever 69, the liftingroller 72 raises the upper run 3" into a position in which thefrictional connection is released, thereby ensuring that the run 3" isdefinitely freed from the pulley 5. During the pivoting movement of thelever 69 which releases the frictional connection, the lower run 3 movesaway from the V-belt pulley 5 by gravity, to a greater or lesser, but:in any case sufficient, extent. The lever 69 is displaced or pivoted,by means of a rod 67 which is pivoted to another arm thereof, althoughthe rod 67 and lever 69 may, of course, be connected by methods otherthan that illustrated.

In FIG. 1 the V-belt 3 is shown in broken lines in the position where itextends over a plurality of pulleys 5 of drive wheels 2 with africtional connection, and is shown in solid lines in the position wherethe connection between the pulley 5 and the belt 3 is released.

When the drive roller 2 is to be driven, the lever 69 is moved into thebroken line position by the force of a spring 73, so that the V-belt 3is guided onto the pulley 5 by the spring bias. The spring 73 bears onthe stop 74.

FIG. 2 shows a single-plate clutch between the V-belt pulley 5 and adrive sprocket 8, as a further example of the disconnection of thedriving force and the drive wheel 2 according to the invention. Thatportion of the clutch illustrated above the central section line of FIG.2 is shown disengaged and is shown engaged below the section line of HO.2. The pulley 5 is again fixed to the drive wheel 2. The verticalposition of the lever 74' (dotted lines) corresponds to the lockedstate, and its inclined position (solid lines) to the uncoupled state.

The lever 74, together with a shaft 74" and a lever member 74", forms arigid component mounted on a support 75. The member 74 is linked by afulcrum pin 76 to a lever 77, which carries a pin 78 at the other end. Ashaft 79, on which the drive wheel 72 is mounted on the support rail 1,also displaceably supports a sliding member 80. The latter acts, bymeans of a ball bearing 81, on a spring 82, having a disc 83 which isapplied to the sprocket 8. A clutch lining 84 is provided on theopposite side of the sprocket; in the engaged condition it cooperateswith a surface of the V-belt pulley 5.

If the drive for the drive wheels provided with clutch elementsaccording to the invention is interrupted as described above-as is thecase with the drive wheels in an accumulation section-the pallets 18being conveyed over them come to a standstill.

FIG. 3 shows a brake which is mounted on part of the pulley 5 notcontacted by the V-belt 3. It is actuated by a bar 65 connected to anarm 86. The arm 86 is, in turn, linked by a bearing 87 to the supportrail 1. At the opposite end it is also fixed to a brake shoe 88 havingan arcuate wearing surface 88'. The shoe is drawn back into its releaseposition by a spring 89, so that the bar has to be compression loaded inorder to engage the brake.

As illustrated in FIG. 4, the brake shoe wearing surface 88' is wedgeshaped, so that it can fit snugly into the wedgeshaped groove in theV-belt pulley 5. When the brake comes into action, the drive wheel 2 isbraked, since it is fixedas already mentioned-to the pulley 5.

The brake illustrated in FIGS. 3 and 4 may be provided on the drivewheels shown in FIGS. 1 and 2. But it is quite possible as illustratednot to provide all the drive wheels 2 with such brakes. Care must thenbe taken, however, to ensure that the brakes are distributed over theindividual wheels 2, in such a way that out of the wheels supporting apallet there is always one which has a brake. Operation of the lever 69and the clutch in FIG. 2 is preferably synchronized with that of thebrake in FIGS. 3 and 4. This can be done either by stopping the firstpallet 18 to arrive at an accumulation section by manually operating thelever 69 and clutch in FIG. 2, i.e., purely mechanically, and then-withthe first pallet 18 stationary-by stopping the successive palletsthrough actuation of switches by the first pallet 18, causing thesuccessive levers 69, clutches and brakes to be set in operation. It ispossible, however, for the first pallet 18 also to be stopped byelectrical control means and for the succeeding pallets to be halted asdescribed.

We claim:

I. In an accumulation section of a pallet conveyor system of the typewherein a plurality of individual pallets are separately supported onand moved by a series of drive wheels longitudinally spaced along a setof horizontal rails by means of common drive V-belt means extendingalong said set of rails and normally arranged to impart rotation to allof said drive wheels, the improvement comprising coupling means for atleast one of said drive wheels, said coupling means including V-beltpulley means, means to rotatably mount said V-belt pulley means foroperative engagement with said driven V- belt means and to rotate saidone of said drive wheels when in said operative engagement, said V-beltpulley means including clutching and braking means movable between firstand second positions, said clutching means including roller means tourge the belt means into engagement with the pulley means when in saidfirst position and to allow the belt means to disengage from the pulleymeans when in said second position, said braking means includingfriction means movably mounted to engage with said pulley means whensaid clutching and braking means is in said second position.

2. The invention defined in claim 1, wherein said coupling meansincludes a shaft for said drive wheel and a V-belt pulley attached tosaid shaft, said belt means includes a horizontally extending V-belt forengagement with said pulley, and said clutching means includes pivotedlever means including a roller for engagement with said V-belt fortensioning the belt into driving engagement with the pulley when thelever means is urged in one direction, and a second roller mounted onthe lever means for engagement with the belt for urging the belt out ofengagement with the pulley when the lever means is urged in the oppositedirection.

3. The invention defined in claim 2, wherein said lever means ispivotally mounted on said shaft for the drive wheel.

4. The invention defined in claim 1, wherein said coupling meansincludes a shaft for supporting one of said drive wheels and a pulleymeans rotatably supported on said shaft, said pulley means being inoperative engagement with said driven belt means, said clutch meansincluding a driven plate connected with said drive wheel and a drivingplate connected with said pulley means, said clutch means also includingmeans for axially shifting one of said plates into and out of operativeengagement with the other of said plates.

5. The invention defined in claim 4, wherein said clutch means alsoincludes articulated lever means connected with said one of said platesfor said axial shifting thereof.

6. The invention defined in claim 1, wherein said coupling meansincludes a V-belt pulley rotatably mounted on said horizontal rails andoperatively connected with a drive wheel, and said braking meansincludes a wedge-shaped element and means for shifting said wedge-shapedelement into frictional engagement with the V-belt pulley.

1. In an accumulation section of a pallet conveyor system of the typewherein a plurality of individual pallets are separately supported onand moved by a series of drive wheels longitudinally spaced along a setof horizontal rails by means of common drive V-belt means extendingalong said set of rails and normally arranged to impart rotation to allof said drive wheels, the improvement comprising coupling means for atleast one of said drive wheels, said coupling means including V-beltpulley means, means to rotatably mount said V-belt pulley means foroperative engagement with said driven V-belt means and to rotate saidone of said drive wheels when in said operative engagement, said Vbeltpulley means including clutching and braking means movable between firstand second positions, said clutching means including roller means tourge the belt means into engagement with the pulley means when in saidfirst position and to allow the belt means to disengage from the pulleymeans when in said second position, said braking means includingfriction means movably mounted to engage with said pulley means whensaid clutching and braking means is in said second position.
 2. Theinvention defined in claim 1, wherein said coupling means includes ashaft for said drive wheel and a V-belt pulley attached to said shaft,said belt means includes a horizontally extending V-belt for engagementWith said pulley, and said clutching means includes pivoted lever meansincluding a roller for engagement with said V-belt for tensioning thebelt into driving engagement with the pulley when the lever means isurged in one direction, and a second roller mounted on the lever meansfor engagement with the belt for urging the belt out of engagement withthe pulley when the lever means is urged in the opposite direction. 3.The invention defined in claim 2, wherein said lever means is pivotallymounted on said shaft for the drive wheel.
 4. The invention defined inclaim 1, wherein said coupling means includes a shaft for supporting oneof said drive wheels and a pulley means rotatably supported on saidshaft, said pulley means being in operative engagement with said drivenbelt means, said clutch means including a driven plate connected withsaid drive wheel and a driving plate connected with said pulley means,said clutch means also including means for axially shifting one of saidplates into and out of operative engagement with the other of saidplates.
 5. The invention defined in claim 4, wherein said clutch meansalso includes articulated lever means connected with said one of saidplates for said axial shifting thereof.
 6. The invention defined inclaim 1, wherein said coupling means includes a V-belt pulley rotatablymounted on said horizontal rails and operatively connected with a drivewheel, and said braking means includes a wedge-shaped element and meansfor shifting said wedge-shaped element into frictional engagement withthe V-belt pulley.